If the washer spins then the lid switch and motor both are most likely okay.
You don't give much detail on the not agitating but yes the water level switch must be satisfied to allow the washer to agitate. If you're on the porch with no water then the water level switch will have to be bypassed to allow the washer to agitate.
Extension cords can be a problem. The washer will not be able to draw the power to run, especially in agitation, if a long extension cord is use. A 50 foot long extension cord will not work but a 10-15 foot heavy duty cord (not a skinny lamp cord) should be okay to test the machine for a short time.
To access the console you will need a putty knife to push in two clips on the corner of the console. See image below.
Remember to unplug the washer first.
The water level switch has a clear plastic hose and 3 wires to it. The wire colors are violet, pink and tan. If you feel comfortable and confident doing so you can put a small jumper wire between the violet and the tan wire. With these two wires jumped, and taped with electrical tape so as not hit anything metal, the washer will think the tub is full of water and you can check the agitation cycle.
If the motor just hums then if you have access to a volt/ohm meter you can check the voltage to the washer and make sure it is 120 volts.
If the motor hums then with the washer cabinet removed you can disconnect the motor from the transmission. If it runs then the transmission is locked up. If the motor doesn't run and still just hums then the motor is most likely bad. The pump should be okay since it spins okay.
If any additional questions come up then submit another question with additional details for further assistance.